Preparation of Bulk Glassy Pd₄₀Ni₁₀Cu₃₀P₂₀ Alloy of 40 mm in Diameter by Water Quenching

抄録

Cylindrical glassy alloys with diameters up to 40 mm were prepared for a Pd₄₀Ni₁₀Cu₃₀P₂₀ alloy with a high reduced glass transition temperature (T_g⁄T_m) of 0.71 by water quenching the molten alloy in the quartz tube. The bulk glassy alloy with a diameter of 40 mm exhibits good metallic luster on the outer surface. Neither cavities nor voids are seen over the whole inner region and no contrast revealing a crystalline phase is seen over the transverse cross section. The glass transition temperature (T_g), crystallization temperature (T_x), the temperature interval of the supercooled liquid region (ΔT_x=T_x−T_g) and the melting temperature (T_m) are measured to be 575, 95 and 804 K, respectively, for the Pd₄₀Ni₁₀Cu₃₀P₂₀ alloy with a diameter of 40 mm. The deviation of Cu content from 30 at%Cu in the Pd₄₀Ni_40−xCu_xP₂₀ system causes a steep increase in T_m and a decrease in T_g⁄T_m, leading to the decrease in the glass-forming ability. The successes of finding the new Pd–Cu base alloy composition with the large ΔT_x and T_g⁄T_m values and preparing the bulk glassy alloy with a diameter of 40 mm are encouraging for the future development of glassy alloys.